<!--首页内容-->
<style>
    .where{
        position: absolute;
        top: 30px;
        left: 8%;

        width: 100%;
        height: 100%;
    }

    .box{
        background-color: rgba(214, 255, 255, 0.562);

        width: calc(100% - 240px);
        height: calc(100% - 10px);  /* 高度通过实际情况计算决定 */

        border-radius: 20px 20px 0px 0px;
    }

    .content{
        position: relative;

        top: 20px;
        left: 3.3%;
    }
</style>
<div id="index">
    <div class="where">
        <div id="box" class="box mdui-shadow-4 mdui-hoverable">
            <div class="content">
                <div>Hello guys~</div>
            </div>
        </div>
    </div>
</div>